1. Field of the Invention
The present invention relates to a metal-sawing machine, and more particularly, to a metal-sawing machine having a saw carrier capable of rocking in the cutting plane with respect to a work to be cut, such that the saw blade is caused to pass through the work in an efficient manner by following a desired arch-like path or trace.
2. Description of the Prior Art
It is known in the art to employ a saw carrier capable of rocking with respect to a work. This type of metal-sawing machine cuts a work more efficiently than the conventional sawing machines which cut a work in the simple horizontal movement of saw blade. As shown in FIG. 1, in such conventional cutting methods the blade edge comes into contact with the whole section of the work with the result of causing a large drag therebetween. In addition, the blade edge is likely to slip on the surface of the work. On the other hand, the adoption of a rocking saw blade has eliminated this drawback, because the blade edge keeps contact with relatively small portion of the section of a work with the result of reducing the cutting drag. In addition, the slipping of saw edge has been avoided. In this way the cutting efficiency has been considerably improved. For effecting such rocking motion of saw blades there are many devices; among which the crank system is in common use. For example, the Japanese laid-open patent specification No. 54-137786 discloses a typical example thereof. Under the crank system, however, it is difficult to lead the saw blade exactly in an arch-like manner, and as shown in FIG. 2 its trace seems arch-like, but in fact it is not; the seemingly arch-like trace consists of two straight lines with a curved portion therebetween. When a saw blade is caused to enter a work in such an inexact arch-like manner, the contact of the blade edge with the work is likely to differ in the see-saw motion of the saw blade as indicated by the letter l. In addition, the rocking speed is different between in the central portion and at opposite end portions, and the adjustment is difficult. Furthermore, the crank mechanism requires a relatively long distance between the crank section and the working section of the saw blade. Consequently, a large moment of force is likely to occur under the cutting load, and consequently, undesirable vibrations of the saw carrier are amplified to make noise and cause cutting errors.
The present invention is directed to the solution of the problems mentioned above with respect to the conventional saw-blade rocking system, and has for its object to provide an improved metal-sawing machine in which the saw blade can rock along an ideal arch-like trace with respect to a work.
Another object of the present invention is to provide an improved metal-sawing machine in which the mode of a see-saw motion of the saw blade can be predetermined as desired.
A further object of the present invention is to provide an improved metal-sawing machine in which the saw carrier can smoothly rock without causing undesirable vibrations.
Other objects and advantages of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description and specific embodiments are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.